Stool



FIG. 1 is a front perspective view of a stool according to the design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a back elevation view thereof;

FIG. 4 is a right side elevation view thereof;

FIG. 5 is a left side elevation view thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a bottom plan view thereof; and,

FIG. 8 is a back perspective thereof. 

CLAIM The ornamental design for a stool, as shown. 